There is a continuous trend in telephony to devise ways to make a customer's telephone service more accessible. With current telephone systems, for example, a subscriber is no longer bound to obtain services only at a fixed location, and in many cases the subscriber can access long-distance and certain specialized calling features from virtually any telephone.
Such access is usually dependent on the use of an authorization code, generally in the guise of a credit card number, although that is not necessarily the case, and other authorization and billing numbers may be employed. Access is gained to the desired service by entry of a credit card number (or other authorization code, or by a combination of access and authorization codes) from the telephone at which the feature or service is desired to be used. If the telephone system is able to verify that the entered number, or code, is valid, then the service or feature is made available for use.
Unfortunately, this ease of access lends itself to fraudulent use of the credit card number or authorization code. Obviously, unless some other controls are imposed, an unscrupulous person who knows the number or code can access and use the service without charge. This works to the detriment of both the service provider (e.g., the long distance carrier) and the card holding subscriber. The service provider gains no revenue from the unauthorized use, may in fact become liable for such things as access charges, and potentially has its network congested with fraudulent traffic. The subscriber, on the other hand, faces a bill for services not obtained and the difficulties attendant to that.
The problem cannot be underestimated, and there is, in fact, a virtual "underground" industry which operates on this kind of fraudulent calling. The various ways that calling card and authorization numbers find their way into unscrupulous hands need not be discussed here, but suffice it to say that telephone "credit card fraud" and other forms of fraudulent use present pervasive problems for the telephone carriers, particularly the long distance carriers. Solutions continue to be sought.
One of the current methods of fraud control is to simply remove credit card numbers against which it is suspected that fraudulent calls are being charged (i.e., their use is blocked). In some cases, the subscriber's card may be taken out of service only if the subscriber cannot be reached for verification. In other cases, however, because of the high rate of fraud and the pattern of calling, control is imposed by a wholesale denial of calling privileges. It might be determined, for example, that fraudulent calls to certain geographic areas from certain calling numbers are so problematic that all calls meeting those criteria should be blocked. The criteria for blockage are varied, and the decisions for blockage might be based on such things as the originating switch, the call's originating information digits, or the class of service. This is a simple, but unsatisfactory, response to the fact that an inordinately high percentage of calls in certain cases (e.g., to certain countries) are fraudulently made.
With these methods there is a trade-off between customer service and fraud prevention. If monitoring is tightened and cards or authorization numbers are taken down aggressively, fraud is lowered, but revenue to the carrier is lessened, and innocent customers whose service has been affected by the sweeping denial are frustrated and angry at being unable to obtain full service. Thus, among other things, totally blocking high-risk countries reduces fraud but results in a less marketable product for the carrier.
The present invention therefore seeks to provide a method for controlling telephone charge card and other similar calling fraud so that there is less chance for unintended discrimination against authentic callers (i.e., those truly entitled), but by which there remains a high probability of denying the privilege to the inauthentic, or fraudulent, callers.